Information on 1 John

The relationship of 1 John to the fourth gospel has been the subject of much scholarly debate. Kummel argues that the gospel and the letter are from the same author (Introduction to the New Testament, pp. 442-5). Norman Perrin presents a solution that connects the redactor of John with the author of the letter (The New Testament: An Introduction, pp. 222-3):

Are the gospel and letters from the same author? They have a unity of general style, tone, and thought that seems to indicate they are, especially in the case of the letters and the discourses in the gospel. But a closer examination reveals a poverty of style in the first letter compared to the gospel - "the author works to death a few favorite constructions, and his vocabulary is more limited than that of the gospel" - and some real differences in thought. The latter aspect of the matter is particularly important since these differences concern eschatology and the sacraments. The author of the letter has a strong hope for the future, a version of the traditional Christian hope for the parousia (2:17, 18, 28; 3:2, 3; 4:17), and he has a great interest in the sacraments of the church (2:12, 20, 27; 3:9; 5:1, 6). In the gospel of John the main thrust is toward the denail of the hope of the parousia, on the grounds that the first coming of Jesus was the decisive event and no further coming, no further judgment, is to be expected (3:16-21, 36, and elsewhere). But throughout the gospel are individual sayings that express the more traditional Christian hope (5:27-29; 6:39-40; 44b, 54; 12:48). Similarly with the sacraments: the gospel as a whole puts its major emphasis on the idea that men are brought to faith by their response to the church's proclamation (3:31-36 and elsewhere), and has no particular concern for the sacraments. Yet the words "water and" in 3:5 make that verse an unmistakable reference to baptism, where no such reference exists apart from those two words; 6:51b-58 makes the discourse on the bread of life sacramental, whereas without those verses it is not; and 19:34b-35 introduces an allusion to baptism as it interrupts the continuity of the narrative.

These indications suggest that the gospel has been redacted from an original text with no future parousia hope or concern for the sacraments, and that such a hope and concern were introduced into the gospel by the author of the first letter. If this is the case (and it is all very tentative), the main text of the gospel is by one author and the first letter by another. Are either of these authors the "presbyter" who wrote the second and third letters? There are similarities of language and thought, yet there are small subtle differences. We simply do not know; the most we can say is that probably at least two authors are involved in the gospels and letters of John, and perhaps three. What is important is that the similarities of style, tone, and thought point to the existence of a Johannine "school." Whether the final form of these texts is the work of one author, or two, or three, their ideas, theology, contents, tone, and style have taken shape not in the mind of one man, but in a group, probably formed of one strong leader and a few intimate followers.

Raymond Brown states (An Introduction to the New Testament, pp. 389-390):

Most scholars think the Johannine Epistles were written after the Gospel. More precisely, I would place I and II John in the decade after the body of the Gospel was written by the evangelist (ca. 90) but before the redaction of the Gospel (which may have been contemporaneous with III John, just after 100). What particularly differentiates I and II John from the Gospel is the change of focus. "The Jews" who are the chief adversaries in the Gospel are absent; and all attention is on deceivers who have seceded from the community, and by so doing have shown a lack of love for their former brothers and sisters.

Although some have proposed a reverse sequence, most contemporary commentators assume that I John was written after the fourth gospel. The terminus ad quem for I John is provided by Polycarp, who presupposes I John 4:2 in Phil 7:1, and by Papias, who used texts from I John according to Eusebius in HE 3.39.17. This places the letter sometime in the first quarter of the second century.